The number of Romanian and Bulgarian migrants expected when the UK opens its doors next January was put at just 12,700, according to long-hidden figures.

Communities Secretary Eric Pickles said the estimates, revealed yesterday after months of cover-up by ministers, were drawn up by Labour after comparing the two countries to Poland, which has sent around one million people to the UK.

The document predicts just 4,613 Bulgarians, out of a population of 7.5million, will come to Britain every year, along with 8,156 Romanians – a tiny fraction of its 21.4million inhabitants.

Addressing Westminster journalists, Mr Pickles said he had ‘no confidence’ in the figures and that was why ministers chose not to publicise them, though he said they were slipped out on a Whitehall website in 2011.